Soda Can Rocket
William Mook
I just came back from the shop watching the metal parts of a product
I've designed being cut on an automated plasma cutter. I took the
parts bent them into shape with a small press. Fit them together.
MIG welded the sub assemblies into near finished form. Including
turning a few of them on the lathe for detailed dimensioning. Ground,
sanded, polished the subassemblies. Applied surface treatment.
Throughout all of this I wondered what sort of small, high capacity
rocket I could build.
We spoke last summer of an SSTO. Would TSTO add too much complexity?
And, since last summer I've had the opportunity to take make some room
temperature vulcanizing rubber molds and use them to layup some
fiberglass shapes. These were special concentrators we're building
for an experimental solar power system. But, I was thinking about
Scott Lowther's comment about fiberglass.
I was thinking that a tiny metal upper stage - with foamed ceramic
outer coating - and a larger fiberglass first stage - with ablative
resin coating - might be possible. H2O2 and Jet Fuel would be the
propellant. Special finish on the tank interiors to stabilize the
H2O2 and keep the Jet Fuel from peeling things too badly.
I still like the ROTON concept as related by MIT students! Great for
the first stage. Or maybe even an add on. A blow down rocket with a
prop turned by a turbine running of f of rocket exhaust that's dropped
at Max Q or something.
Ian Stirling
>Throughout all of this I wondered what sort of small, high capacity
>rocket I could build.
>We spoke last summer of an SSTO. Would TSTO add too much complexity?
SSTO does not work, without utterly unobtainable propellants.
(nuclear, metastable H, ...)
I'm not sure it's even possible, assuming reasonable near-term materials.
(and by this I mean nanotube composite, ...)
Atmospheric drag is HIGH for small rockets.
<snip>
>I was thinking that a tiny metal upper stage - with foamed ceramic
>outer coating - and a larger fiberglass first stage - with ablative
>resin coating - might be possible. H2O2 and Jet Fuel would be the
Why coated?
You certainly don't need any coating leaving the atmosphere.
For a small rocket to have any chance at all to get up there, drag
is paramount, as are throttleable engines.
You accellerate to M0.8 or so, as rapidly as you can, then carry on up
until 30Km or so, when you open the throttle again.
Trying to accellerate through the thick atmosphere at say 3G may only
buy you a few tens of meters a second, compared with the thrust that
is only a little more than weight.
This has the side-effect of reducing max Q, and heating.
It also means that staging can occur in a much, much more benign enviroment.
I do think that appropriately designed rockets can be very small.
For example, I wonder about model rocket aircraft engines for a
zeroth stage.
These are relatively inexpensive, moderately high thrust (50Kg), and
may be of use for a zeroth stage flyback.
With more aggressive optimisation than I'm trying for, I think a
three stage (1Kg payload, 5Kg/25Kg/125Kg total loaded mass)
launcher would be quite possible.
In the design I'm progressing (very slowly) on, there would be an
extra 625Kg stage, to make the margins looser.
(or, a 1Kg stage with 200g payload.)
A prize from coke, to launch into orbit a standard coke-can would be
interesting :)
--
http://inquisitor.i.am/ | mailto:inqui...@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------
Money is a powerful aphrodisiac, but flowers work almost as well.
-- Robert A Heinlein.
William Mook
> William Mook <wm...@my-deja.com> wrote:
> >Any further work done on Soda can rockets?
> <snip>
> >Throughout all of this I wondered what sort of small, high capacity
> >rocket I could build.
>
> >We spoke last summer of an SSTO. Would TSTO add too much complexity?
>
> SSTO does not work, without utterly unobtainable propellants.
> (nuclear, metastable H, ...)
> I'm not sure it's even possible, assuming reasonable near-term materials.
> (and by this I mean nanotube composite, ...)
>
> Atmospheric drag is HIGH for small rockets.
>
> <snip>
> >I was thinking that a tiny metal upper stage - with foamed ceramic
> >outer coating - and a larger fiberglass first stage - with ablative
> >resin coating - might be possible. H2O2 and Jet Fuel would be the
>
> Why coated?
> You certainly don't need any coating leaving the atmosphere.
> For a small rocket to have any chance at all to get up there, drag
> is paramount, as are throttleable engines.
> You accellerate to M0.8 or so, as rapidly as you can, then carry on up
> until 30Km or so, when you open the throttle again.
This is a good idea.
> Trying to accellerate through the thick atmosphere at say 3G may only
> buy you a few tens of meters a second, compared with the thrust that
> is only a little more than weight.
I agree.
> This has the side-effect of reducing max Q, and heating.
Yes.
> It also means that staging can occur in a much, much more benign enviroment.
Possibly.
> I do think that appropriately designed rockets can be very small.
> For example, I wonder about model rocket aircraft engines for a
> zeroth stage.
Not enough total impulse in my estimation.
> These are relatively inexpensive, moderately high thrust (50Kg), and
> may be of use for a zeroth stage flyback.
> With more aggressive optimisation than I'm trying for, I think a
> three stage (1Kg payload, 5Kg/25Kg/125Kg total loaded mass)
> launcher would be quite possible.
Well, its easy to figure. If you know your total mass, the propellant
mass, and the exhaust speed - its easy to figure your ideal final
speed. Gravity and air drag losses can be taken from that, but you
won't do better than the ideal calculated in this way.
> In the design I'm progressing (very slowly) on, there would be an
> extra 625Kg stage, to make the margins looser.
> (or, a 1Kg stage with 200g payload.)
>
> A prize from coke, to launch into orbit a standard coke-can would be
> interesting :)
I like your idea of low speed vertical ascent until you reach
sufficient altitude.
How about two small model aircraft engines linked together each
turning a prop in opposite directions for the zeroth stage? You'd
have a gyro and a few other gizmos drawn from the model helicopter
market. I don't know if you'd need to go Mach 0.8 - but if you could
get up to say 0.4 to 0.5 - say 150 mph - 2.5 miles per minute -
straight up - that'd get you to 25 miles in about 10 minutes.
The double fan would then drop off, drop back down, at low throttle.
You could even throttle up to come to a soft touchdown.
A small ablative coated rocket engine with blow down propellant feed
burning H2O2 and Jet Fuel - would then ignite at altitude. It might
even spin to pressurize the rocket engine - ala Cyclojet.
John Carmack
> Any further work done on Soda can rockets?
I was wondering if this would come up again. Talking about tiny
orbital vehicles projects as if you can just go out and do them is not
helping anyone make any progress. Pick one of the necessary
intermediate steps, and actually work on it:
Fire a small biprop engine with active cooling that can run for the
required multiple-minute burn time for orbital shots. Ablative isn't
really an option for a very small orbital motor, because the ablation
rate is constant irrespective of size, and it would consume the entire
small engine. It took XCOR quite a while to work out their cooled
engines. Personally, I would lean towards an uncooled chamber /
nozzle of iridium / rhenium / carbon-carbon for a high performance
micro vehicle, but that requires a rather large capital outlay.
Heck, getting any liquid fueled engine running smoothly and
efficiently on the test stand puts you in a select club. Make one
with modest (by newsgroup standards) performance, and I'll give you
$2000: http://www.armadilloaerospace.com/Hppa2.htm
Fly an actively stabilized and guided vehicle to any altitude. It
took Armadillo eight months to work out our peroxide monoprop thruster
based control systems for hover and translation.
Fly-straight-to-orbit may be a bit easier, but not too much.
Build a radio frequency based attitude sensing system, so the bulky
and expensive fiber optic gyros can be dispensed with.
Fly a biprop vehicle to 50,000'. I don't think an amateur has ever
done this, and in any case, it isn't trivial. Hybrids have flown
higher, and if you give up on SSTO as a goal, they sound appealing
from a development time standpoint.
Build a functional high mass fraction demonstrator. Silly numbers are
often thrown about, but I don't think an amateur has build a flying
rocket with a mass fraction of 10, even an unguided solid or peroxide
monoprop.
Fly a micro-roton demonstrator. We are considering pursuing this at
Armadillo.
Pick one and have at it, I would love to hear about the endeavor.
I dare you. :-)
John Carmack
www.armadilloaerospace.com
William Mook
> William Mook wrote:
> > Any further work done on Soda can rockets?
>
> I was wondering if this would come up again. Talking about tiny
> orbital vehicles projects as if you can just go out and do them is not
> helping anyone make any progress. Pick one of the necessary
> intermediate steps, and actually work on it:
Yes.
> Fire a small biprop engine with active cooling that can run for the
> required multiple-minute burn time for orbital shots. Ablative isn't
> really an option for a very small orbital motor, because the ablation
> rate is constant irrespective of size, and it would consume the entire
> small engine.
What about adding thin film vapor cooling? Here you inject a vapor
layer between the rocket nozzle and exhaust gases. This seems like it
would be simpler than regenerative cooling and give your ablative
system a chance to work on smaller scales.
Rather than figure everything out in my armchair, I think I'll have to
do a bit of cut and try work. I just don't want to get killed doing
that.
> It took XCOR quite a while to work out their cooled
> engines.
I bet.
Personally, I would lean towards an uncooled chamber /
> nozzle of iridium / rhenium / carbon-carbon for a high performance
> micro vehicle, but that requires a rather large capital outlay.
http://www.rhenium.com/Sheet/Moly_Rhenium/MoRe-sheet.html
Has some information on Moly/Rhe foils. How difficult would it be to
shape and weld these things? Could we spin weld pieces together?
Would I be able to cut shapes using a plasma torch?
A can imagine taking a foil and turning it against a mandrel to
produce a delaval nozzle. Then take the mandrel apart and remove it
from the engine. Then, cut a hole in the nozzle to attach propellant
feedlines.
For larger engines I'd need to shape and join separate pieces.
Spinning the pieces against one another until they weld is one
possiblity that occurs to me, but I don't know if it would really
work. I might just start a fire. Would I need a nitrogen bath?
Could I electroplate rehenium onto a substrate? That would let me
take plates and 'join' them by electroforming. Rhenium should be
electronically similar to Manganese and electrolytes that work for one
should work for the other.
What do you think of mild carbon steel with a thermal barrier coating
of Yttrium Oxide and Ziconium Oxide with a top coat of Metco 204NS
bonded with Praxair Ni-346-1?
The substrate is easy to work and form, you could build it up in
sections, coat it, and then join it.
> Heck, getting any liquid fueled engine running smoothly and
> efficiently on the test stand puts you in a select club.
Yes.
> Make one
> with modest (by newsgroup standards) performance, and I'll give you
> $2000: http://www.armadilloaerospace.com/Hppa2.htm
Cool.
> Fly an actively stabilized and guided vehicle to any altitude. It
> took Armadillo eight months to work out our peroxide monoprop thruster
> based control systems for hover and translation.
Do you have any technical references on this?
> Fly-straight-to-orbit may be a bit easier, but not too much.
Easier and different.
> Build a radio frequency based attitude sensing system, so the bulky
> and expensive fiber optic gyros can be dispensed with.
I like this idea and I've given it a little more thought. This is the
way to go for guidance in my estimation.
> Fly a biprop vehicle to 50,000'. I don't think an amateur has ever
> done this, and in any case, it isn't trivial.
FAA requires licensing for this (or any rocket with more than a model
rocket's impulse or built of anything but cardboard!)
> Hybrids have flown
> higher, and if you give up on SSTO as a goal, they sound appealing
> from a development time standpoint.
Have they obtained FAA flight license? If so, a detailed legal
reference would help others. I haven't found one lawyer who is
familiar with this topic.
> Build a functional high mass fraction demonstrator. Silly numbers are
> often thrown about, but I don't think an amateur has build a flying
> rocket with a mass fraction of 10, even an unguided solid or peroxide
> monoprop.
Interesting. A thin foil moly/rhe engine would help. Blow down H2O2
held in a thin Al foil tank. Attaching the engine to the tank would
involve some interesting structures given their different coefficients
of expansion and the temperature of the engine. I would try first to
wrap the engine in some sort of insulating sleeve, hold that tight
with an aluminum strap that is structurally connected to the tank.
Would NOMEX work as the sleeve material?
> Fly a micro-roton demonstrator. We are considering pursuing this at
> Armadillo.
>
> Pick one and have at it, I would love to hear about the endeavor.
> I dare you. :-)
>
> John Carmack
> www.armadilloaerospace.com
Again, I won't take a dare to get killed. Also, while I have a site
on an Ohio farm available this season, I haven't been able to get all
the permits I need to do the things I want. Even static testing
requires that propellants be accumulated and so forth. Any help in
how to keep legal doing these things would be helpful. Also, what
about property insurance?
Scott Lowther
> What about adding thin film vapor cooling? Here you inject a vapor
> layer between the rocket nozzle and exhaust gases. This seems like it
> would be simpler than regenerative cooling...
Gah. This would actually probably be harder than regen, because it needs
a large number of *very*small* holes to work.
> Personally, I would lean towards an uncooled chamber /
> > nozzle of iridium / rhenium / carbon-carbon for a high performance
> > micro vehicle, but that requires a rather large capital outlay.
>
> http://www.rhenium.com/Sheet/Moly_Rhenium/MoRe-sheet.html
>
> Has some information on Moly/Rhe foils. How difficult would it be to
> shape and weld these things? Could we spin weld pieces together?
> Would I be able to cut shapes using a plasma torch?
Bah. Do it this way:
http://www.ultramet.com/rockets.htm
Heavy refractory metals have a distinct dislike for most forming
operations such as bending sheets or machining. However, obviously,
other means are available.
Ian Stirling
>
> William Mook wrote:
>
>> What about adding thin film vapor cooling? Here you inject a vapor
>> layer between the rocket nozzle and exhaust gases. This seems like it
>> would be simpler than regenerative cooling...
>
> Gah. This would actually probably be harder than regen, because it needs
> a large number of *very*small* holes to work.
I vaguely recall in the NACA digital archives reading about an annular
injector, but vapour cooling has another problem: If the vapour is cool,
it's not burning.
If it's not burning, it's at least largely wasted.
And in common with ablative coatings, things get worse for small rockets.
The losses go up quite dramatically.
>> Personally, I would lean towards an uncooled chamber /
>> > nozzle of iridium / rhenium / carbon-carbon for a high performance
>> > micro vehicle, but that requires a rather large capital outlay.
Carbon-carbon is nice stuff, if only there was a nice tabletop process
for it.
Ir/Re nozzles make sense, but only for the very smallest rockets.
They are just too expensive for thrust of more than a few kilos, unless
recovery can be done.
--
http://inquisitor.i.am/ | mailto:inqui...@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------
Two parrots sitting on a perch. One asks the other, "Can you smell fish?"
William Mook
> William Mook wrote:
>
> > What about adding thin film vapor cooling? Here you inject a vapor
> > layer between the rocket nozzle and exhaust gases. This seems like it
> > would be simpler than regenerative cooling...
>
> Gah. This would actually probably be harder than regen, because it needs
> a large number of *very*small* holes to work.
Yep. But, you can make large numbers of small holes with laser
cutters. ALthough I haven't tried it with Re foils.
> > Personally, I would lean towards an uncooled chamber /
> > > nozzle of iridium / rhenium / carbon-carbon for a high performance
> > > micro vehicle, but that requires a rather large capital outlay.
> >
> > http://www.rhenium.com/Sheet/Moly_Rhenium/MoRe-sheet.html
> >
> > Has some information on Moly/Rhe foils. How difficult would it be to
> > shape and weld these things? Could we spin weld pieces together?
> > Would I be able to cut shapes using a plasma torch?
>
> Bah. Do it this way:
> http://www.ultramet.com/rockets.htm
>
> Heavy refractory metals have a distinct dislike for most forming
> operations such as bending sheets or machining. However, obviously,
> other means are available.
Yep. These folks use CVD, which is a good way to go. What does a
small engine cost from Aerojet General? Are there spares they could
let go for cheap?
You could have nitric acid and hydrazine pressurized to 3 MPa in
composite tanks and fed into a small engine. Without pumps,
regenerative cooling, and so forth, the whole vehicle mass should be
gotten down to 7% or less.
John Carmack
> What about adding thin film vapor cooling? Here you inject a vapor
> layer between the rocket nozzle and exhaust gases. This seems like it
> would be simpler than regenerative cooling and give your ablative
> system a chance to work on smaller scales.
>
I'm sure it would help, but I don't know how much. It would be an
interesting research project. However, spending a lot of ingenuity
fighting minimum gauge problems probably isn't the best use of time.
I think that the decision to be targeting manned rocket vehicles at
Armadillo has saved us from a lot of diversions. Knowing that we are
going to have 150+ pounds of inert mass in the vehicle keeps us from
getting into costly weight saving experiments. Just not caring that
our electronics box weighs over fifteen pounds has been nice.
> What do you think of mild carbon steel with a thermal barrier coating
> of Yttrium Oxide and Ziconium Oxide with a top coat of Metco 204NS
> bonded with Praxair Ni-346-1?
>
I doubt that would work, because the oxide insulators will still
transmit the heat to the base metal, it will just take some time. The
ir/re nozzles are nice because they can stay at thermal equilibrium
almost indefinitely.
> > Fly an actively stabilized and guided vehicle to any altitude. It
> > took Armadillo eight months to work out our peroxide monoprop thruster
> > based control systems for hover and translation.
>
> Do you have any technical references on this?
Most of the design decisions are noted in the various updates on our
web page, but it is a lot of text to search through.
> > Fly a biprop vehicle to 50,000'. I don't think an amateur has ever
> > done this, and in any case, it isn't trivial.
>
> FAA requires licensing for this (or any rocket with more than a model
> rocket's impulse or built of anything but cardboard!)
You can fly very large vehicles under the standard waiver process
without needing a launch license:
http://www.nar.org/cabinet/waiverinst.html
The total impulse limits are very high, but the burn time limit of 15
seconds becomes the big issue where you need to talk to AST.
> > Build a functional high mass fraction demonstrator. Silly numbers are
> > often thrown about, but I don't think an amateur has build a flying
> > rocket with a mass fraction of 10, even an unguided solid or peroxide
> > monoprop.
>
> Interesting. A thin foil moly/rhe engine would help. Blow down H2O2
> held in a thin Al foil tank. Attaching the engine to the tank would
> involve some interesting structures given their different coefficients
> of expansion and the temperature of the engine. I would try first to
> wrap the engine in some sort of insulating sleeve, hold that tight
> with an aluminum strap that is structurally connected to the tank.
> Would NOMEX work as the sleeve material?
>
A monoprop peroxide vehicle wouldn't need anything tricky at all,
because you can use stainless steel (or even brass) uncooled. It just
hasn't been done. All the "other stuff" on a vehicle, even a dumb
vehicle, adds up fast in mass.
John Carmack
www.armadilloaerospace.com
Scott
>Yep. These folks use CVD, which is a good way to go. What does a
>small engine cost from Aerojet General? Are there spares they could
>let go for cheap?
How small and cheap are you looking for? No one in the business has spares
they let go cheap. They sell those to the next customer in line, at full
price.
Even a 0.2 lbf monoprop thruster is going to run you over $25k. When you
get into the biprop thrusters, you are talking at least $250k for a 100 lbf
thruster.
-S
William Mook
Well, at those prices, the next question is, what's a homebrew CVD
setup go for? You can get a lot of work done at a machine shop for
$250k!
Al Montestruc
A balloon or a private aircraft as a launch platform is better.
Build a light glider that will hold the rocket with a long teather.
Fly as high as the plane can practically go, fly the glider higher
like a kite. You should be able to get to at least 20,000 feet with a
propjob, and that is above most of the air.
A balloon can go higher, but you lose contol of where you launch from.
Henry Spencer
William Mook <wm...@my-deja.com> wrote:
>Well, at those prices, the next question is, what's a homebrew CVD
>setup go for?
"If you have to ask, you can't afford it."
--
Many things changed on Sept. 11, but the | Henry Spencer he...@spsystems.net
importance of freedom did not. -SpaceNews| (aka he...@zoo.toronto.edu)
Henry Spencer
Scott Lowther <lex...@ix.netcom.com> wrote:
>> What about adding thin film vapor cooling? Here you inject a vapor
>> layer between the rocket nozzle and exhaust gases. This seems like it
>> would be simpler than regenerative cooling...
>
>Gah. This would actually probably be harder than regen, because it needs
>a large number of *very*small* holes to work.
Indeed, the classical problem with such schemes -- they're very attractive
on paper, at least for large engines -- has been getting accurate *uniform*
coolant injection.
The ultimate extension of this is transpiration cooling, where you use a
porous wall with coolant seeping out through it. Making this work well is
really hard; in particular, there are flow instabilities which tend to
reduce flow in hot areas, just the opposite of what you want. It's seen
a little bit of use in injector faces, and not otherwise.
Note, though, that almost all rocket engines (even the regeneratively
cooled ones) use "curtain cooling", where the outermost ring of the
injector is set up to run very fuel-rich, so there is a cool layer along
the wall.
Bruce Hoult
monte...@lycos.com (Al Montestruc) wrote:
> A balloon or a private aircraft as a launch platform is better.
>
> Build a light glider that will hold the rocket with a long teather.
> Fly as high as the plane can practically go, fly the glider higher
> like a kite. You should be able to get to at least 20,000 feet with a
> propjob, and that is above most of the air.
>
> A balloon can go higher, but you lose contol of where you launch from.
Gliders fairly regularly get to 30,000 - 35,000 ft without bothering
with the powered aircraft (except for the first couple of thousand feet).
Impractical as a scheduled thing, but there are plenty of people here in
NZ or in places such as Minden who could give you maybe a 90% chance of
getting that high in a given week at the right time of year.
Actually, the main obstacle to going higher is that the pilot starts to
need a full body pressure suit.
-- Bruce
Al Montestruc
> In article <c58ec7cf.01112...@posting.google.com>,
> monte...@lycos.com (Al Montestruc) wrote:
>
> > A balloon or a private aircraft as a launch platform is better.
> >
> > Build a light glider that will hold the rocket with a long teather.
> > Fly as high as the plane can practically go, fly the glider higher
> > like a kite. You should be able to get to at least 20,000 feet with a
> > propjob, and that is above most of the air.
> >
> > A balloon can go higher, but you lose contol of where you launch from.
>
> Gliders fairly regularly get to 30,000 - 35,000 ft without bothering
> with the powered aircraft (except for the first couple of thousand feet).
>
> Impractical as a scheduled thing, but there are plenty of people here in
> NZ or in places such as Minden who could give you maybe a 90% chance of
> getting that high in a given week at the right time of year.
Sounds workable, but can you do it with an underwing slung payload of
something like 300kg? That being the rocket+payload.
>
> Actually, the main obstacle to going higher is that the pilot starts to
> need a full body pressure suit.
P-suits can be taylor made, O2 and CO2 scrubbers for the pilot can be
added to the payload.
Bruce Hoult
> Bruce Hoult <br...@hoult.org> wrote in message
> news:<bruce-C2BDBF....@news.paradise.net.nz>...
> > In article <c58ec7cf.01112...@posting.google.com>,
> > monte...@lycos.com (Al Montestruc) wrote:
> >
> > > A balloon or a private aircraft as a launch platform is better.
> > >
> > > Build a light glider that will hold the rocket with a long teather.
> > > Fly as high as the plane can practically go, fly the glider higher
> > > like a kite. You should be able to get to at least 20,000 feet with
> > > a
> > > propjob, and that is above most of the air.
> > >
> > > A balloon can go higher, but you lose contol of where you launch
> > > from.
> >
> > Gliders fairly regularly get to 30,000 - 35,000 ft without bothering
> > with the powered aircraft (except for the first couple of thousand
> > feet).
> >
> > Impractical as a scheduled thing, but there are plenty of people here
> > in
> > NZ or in places such as Minden who could give you maybe a 90% chance of
> > getting that high in a given week at the right time of year.
>
> Sounds workable, but can you do it with an underwing slung payload of
> something like 300kg? That being the rocket+payload.
300 kg migth be a bit much. See, for example:
http://www.schempp-hirth.com/en/flugzeuge/nimbus_4/main.html
As you can see, the Nimbus 4 has an empty weight of 470 kg and a Max
all-up of 800 kg. You'd have to have a pretty light pilot to be able to
carry 300 kg :-)
Of course it will still fly just fine if you go over that, just with the
maximum G loading reduced somewhat from the normal 5 G.
Also, the max weight will be with a lot of weight being water in the
wings. You can't put that much in the fuselage. Well, not without
reducing the max G laoding still further...
I'm not sure how you'd do under-wing. If you get the 4M model then you
can strip out the engine and have a nice fireproof bay just above and
behind the wing.
Other manufacturers make similar machines.
> > Actually, the main obstacle to going higher is that the pilot starts to
> > need a full body pressure suit.
>
> P-suits can be taylor made, O2 and CO2 scrubbers for the pilot can be
> added to the payload
Well, if you're into that, the US altitude record for gliders is around
45000 ft, and that was a *long* time ago. The glider is in the museum
at Boeing field.
-- Bruce
Jerry Irvine
<br...@hoult.org> wrote:
One could scale one up 400% for this mission. An entirely new airplane
would cost less than a first stage motor.
Jerry
>
> Of course it will still fly just fine if you go over that, just with the
> maximum G loading reduced somewhat from the normal 5 G.
>
> Also, the max weight will be with a lot of weight being water in the
> wings. You can't put that much in the fuselage. Well, not without
> reducing the max G laoding still further...
>
> I'm not sure how you'd do under-wing. If you get the 4M model then you
> can strip out the engine and have a nice fireproof bay just above and
> behind the wing.
>
> Other manufacturers make similar machines.
>
>
> > > Actually, the main obstacle to going higher is that the pilot starts to
> > > need a full body pressure suit.
> >
> > P-suits can be taylor made, O2 and CO2 scrubbers for the pilot can be
> > added to the payload
>
> Well, if you're into that, the US altitude record for gliders is around
> 45000 ft, and that was a *long* time ago. The glider is in the museum
> at Boeing field.
>
> -- Bruce
--
Jerry Irvine, Box 1242, Claremont, California USA
Opinion, the whole thing. <mail to:01ro...@gte.net>
Bring common sense back to rocketry administration.
William Mook
Al Montestruc <monte...@lycos.com> wrote
> A balloon or a private aircraft as a launch platform is better.
You won't be able to go as high.
> Build a light glider that will hold the rocket with a long teather.
> Fly as high as the plane can practically go, fly the glider higher
> like a kite. You should be able to get to at least 20,000 feet with a
> propjob, and that is above most of the air.
I think if you want to efficiently attain orbit, you'd throttle back until
you reach 120,000 feet that's six times higher. So, if you're going to use
a high speed prop that's powered by on board oxidizer and fuel, then,
constructing it as a 'zeroth' stage, makes more sense to me. But, there's
no reason you couldn't build the zeroth stage with wings and launch it
horizontally. It would look a lot like what you describe. I doubt if the
wings would be much help past 20,000 feet though, so you'd be lifting them
with your high speed prop for 100,000 feet. It would help to bring the
stage back though! One of the problems with wings is how they scale as
you scale up the rocket. For small soda can rockets they're perfectly
doable. For big ass rockets, you need big ass wings, and that means you pay
a huge structural penalty which far outweighs the structure for rocket
engines to lift an equivalent mass. Consider, wings give you a 10:1 or
maybe a 12:1 advantage at lift off. So, a 100lb thrust can lift say 1,000
lbs with wings. But, a pound of wings produces less thrust than a pound of
rocket engines, so you're not really that far ahead. Especially given the
fact that wings' leverage drops dramatically as you increase airspeed past
Mach 1, and orbital speed is something like Mach 23.
> A balloon can go higher, but you lose contol of where you launch from.
For smaller rockets balloons make more sense absolutely. GPS or inertial
guidance might be used to make this a moot point. But, big ass rockets mean
big ass balloons so don't look for big payloads being launched this way.
Wasn't it the Rockoon program that was proposed as a competitor to Vangaurd?
William Mook
John Carmack wrote:
> You can fly very large vehicles under the standard waiver process
> without needing a launch license:
>
> http://www.nar.org/cabinet/waiverinst.html
Very interesting. Thanks.
> The total impulse limits are very high, but the burn time limit of 15
> seconds becomes the big issue where you need to talk to AST.
If I'm understanding you, the waiver won't work if your total impulse time
is 15 seconds? So, you really can't do too much can you with this waiver.
You're in a box. Gee forces limit you on one side, airspeed on the other.
Consider that V=at, so at 11 gees, and 15 seconds, V=1500 m/sec is your
speed limit. D=1/2V^2/g0 = 0.5 * 2.25e6 / 10 ~ 1e5 m ~ 100 km, well I guess
that's pretty high. But this simple estimate doesn't account for air drag
losses. Da = Cd * 1/2 * rho * V^2 ,
Your ten gees net will fall off dramatically as you build up airspeed.
Then, there's the structural strength needed to carry the monumental airload
as the airspeed builds, which reduces you propellant fraction.
Realistically, you might get near the speed of sound, 300 m/sec under these
conditions, and if your rocket doesn't shake apart, you might get up to 4 or
5 km altitude.
> > > Build a functional high mass fraction demonstrator. Silly numbers are
> > > often thrown about, but I don't think an amateur has build a flying
> > > rocket with a mass fraction of 10, even an unguided solid or peroxide
> > > monoprop.
> >
> > Interesting. A thin foil moly/rhe engine would help. Blow down H2O2
> > held in a thin Al foil tank. Attaching the engine to the tank would
> > involve some interesting structures given their different coefficients
> > of expansion and the temperature of the engine. I would try first to
> > wrap the engine in some sort of insulating sleeve, hold that tight
> > with an aluminum strap that is structurally connected to the tank.
> > Would NOMEX work as the sleeve material?
> >
>
> A monoprop peroxide vehicle wouldn't need anything tricky at all,
> because you can use stainless steel (or even brass) uncooled. It just
> hasn't been done. All the "other stuff" on a vehicle, even a dumb
> vehicle, adds up fast in mass.
Cool. How about aluminum? I'm thinking of an aluminum engine constructed
like a heat pipe with water or some similar wroking fluid circulating to a
light weight annulus radiator. It sounds complicated but its really just
two engine shaped foils one slightly larger than the other with the larger
one jacketing the smaller. A metal cloth between the two, at point on the
expansion nozzle the gas temp falls below the melting point of Al, the cloth
spreads radially outward as a disk, contained heat pipe fashion between the
two walls. If the disk must expand beyond the base of the rocket body,
merely fold it into vanes that parallel the air flow past the rocket's base.
All aluminum construction, with thin tough aluminum foils, hydrogen peroxide
monopropellant. You'd need more than 15 second burn time though.
The base of the rocket would also be equipped with an aluminum turbine/prop
disk. The rocket would drive the turbine at low thrust so that it would
provide prop lift at take off. It would climb at constant speed - about
half sound speed, for miinutes. Then, at altitude, it would drop the disk,
increase thrust, and continue its flight in a way that maximizes speed.
Once all propellant were spent, it would coast to an altitude determined by
its burnout velocity and climb angle.
John Carmack
> > The total impulse limits are very high, but the burn time limit of 15
> > seconds becomes the big issue where you need to talk to AST.
>
> If I'm understanding you, the waiver won't work if your total impulse time
> is 15 seconds? So, you really can't do too much can you with this waiver.
> You're in a box. Gee forces limit you on one side, airspeed on the other.
>
It is generally believed that you can cross 100 km inside these
limitations. You can have a progressive burn, extreme G's at liftoff
(some HPR rockets take >40 Gs with ease), or an interrupted burn with
a coast period.
Tripoli has a special waiver granted for burn times of up to 60
seconds, but you can only launch AP solids or nitrous hybrids under
their current rules.
I am going to be asking AST for a burn time waiver for our work within
a few months. We'll see how it goes.
> Realistically, you might get near the speed of sound, 300 m/sec under these
> conditions, and if your rocket doesn't shake apart, you might get up to 4 or
> 5 km altitude.
The speed of sound is broken routinely with HPR rockets.
> >
> > A monoprop peroxide vehicle wouldn't need anything tricky at all,
> > because you can use stainless steel (or even brass) uncooled. It just
> > hasn't been done. All the "other stuff" on a vehicle, even a dumb
> > vehicle, adds up fast in mass.
>
> Cool. How about aluminum?
Even monoprop peroxide will melt aluminum in an uncooled state, and I
don't think any passive cooling schemes will cut it. You could
regeneratively cool it without too much trouble, but I don't know if
it would be worth it. You can make everything else from aluminum and
just make the catalyst pack and nozzle from something else.
>
> The base of the rocket would also be equipped with an aluminum turbine/prop
> disk. The rocket would drive the turbine at low thrust so that it would
> provide prop lift at take off. It would climb at constant speed - about
> half sound speed, for miinutes. Then, at altitude, it would drop the disk,
> increase thrust, and continue its flight in a way that maximizes speed.
> Once all propellant were spent, it would coast to an altitude determined by
> its burnout velocity and climb angle.
I am pretty keen on prop air-augmentation at the moment, for both
ascent and recovery, and I think we will be flying something based on
that within a couple months.
John Carmack
www.armadilloaerospace.com
Ian Woollard
>>The base of the rocket would also be equipped with an aluminum turbine/prop
>>disk. The rocket would drive the turbine at low thrust so that it would
>>provide prop lift at take off. It would climb at constant speed - about
>>half sound speed, for miinutes. Then, at altitude, it would drop the disk,
>>increase thrust, and continue its flight in a way that maximizes speed.
>>Once all propellant were spent, it would coast to an altitude determined by
>>its burnout velocity and climb angle.
>>
>
> I am pretty keen on prop air-augmentation at the moment, for both
> ascent and recovery, and I think we will be flying something based on
> that within a couple months.
For ascent, Jim Bowery did some simulations that seemed to indicate
that using lift during ascent means you get less altitude- it
optimised down to nothing.
That kinda makes sense to me; you only have a certain amount of
thrust in your fuel- if you use the energy to get lift using a
wing- you have a loss due to the loss-drag ratio of the wing.
Still, it's not enough to optimise one part of the vehicle- you
have to optimise both ascent and descent; it might make sense in
context if you reduce the weight of the vehicle overall.
The other issue that Gary Hudson found was that if you have a top
mounted rocket tipped rotor and you lose power during ascent- the
vehicle tends to violently flip...
> John Carmack
> www.armadilloaerospace.com
John Hare
jo...@idsoftware.com (John Carmack) writes:
>>
>> The base of the rocket would also be equipped with an aluminum turbine/prop
>> disk. The rocket would drive the turbine at low thrust so that it would
>> provide prop lift at take off. It would climb at constant speed - about
>> half sound speed, for miinutes. Then, at altitude, it would drop the disk,
>> increase thrust, and continue its flight in a way that maximizes speed.
>> Once all propellant were spent, it would coast to an altitude determined by
>> its burnout velocity and climb angle.
>
>I am pretty keen on prop air-augmentation at the moment, for both
>ascent and recovery, and I think we will be flying something based on
>that within a couple months.
>
>John Carmack
>www.armadilloaerospace.com
>
Would it be any air-augmentation system the rest of
us would recognize?
John Carmack
> >I am pretty keen on prop air-augmentation at the moment, for both
> >ascent and recovery, and I think we will be flying something based on
> >that within a couple months.
> >
> >John Carmack
> >www.armadilloaerospace.com
> >
> Would it be any air-augmentation system the rest of
> us would recognize?
I talk a bit about it in the latest update:
http://www.armadilloaerospace.com/Updates/dec1_01.htm
Our reference suborbital vehicle design is basically a higher
performance incarnation of the same systems that fly our current
vehicles, but with a hybrid grain augmenting the central lifting
engine. Recovery would be by rear parachute ejection, but it would
need at least two "stages" of parachutes.
As another possible option against this, we have recently started
talking about a tiny monoprop roton vehicle design, because it helps
with both the ascent and the recovery. We are starting to build some
hardware now, and we will almost certainly be flying a few different
configurations next year.
John Carmack
www.armadilloaerospace.com
Bruce Hoult
<01rocket-301...@1cust235.tnt1.rancho-cucamonga.ca.da.uu.net>,
01ro...@gte.net (Jerry Irvine) wrote:
> > > Sounds workable, but can you do it with an underwing slung payload of
> > > something like 300kg? That being the rocket+payload.
> >
> > 300 kg migth be a bit much. See, for example:
> >
> > http://www.schempp-hirth.com/en/flugzeuge/nimbus_4/main.html
> >
> > As you can see, the Nimbus 4 has an empty weight of 470 kg and a Max
> > all-up of 800 kg. You'd have to have a pretty light pilot to be able
> > to
> > carry 300 kg :-)
>
> One could scale one up 400% for this mission. An entirely new airplane
> would cost less than a first stage motor.
Well if you're going to do that, XCOR would I'm sure be delighted to
equip you with a 400 lbf rocket to give you that extra five or ten
thousand feet of altitude...
-- Bruce
Peter Hanely
CVD?
Scott
Peter Hanely wrote in message <3C0B6912...@no-spam.calweb.com>...
>
(snip)
>CVD?
CVD = Chemical Vapor Deposition
Check out Ultramet's web site at www.ultramet.com. They have a section
discussing rocket engine thrust chambers.
Sockboy4
>> If I'm understanding you, the waiver won't work if your total impulse
>time
>> is 15 seconds? So, you really can't do too much can you with this waiver.
Couldn't you launch over international waters and get around this? Though I
suppose that would only work if you are near the coast. Does anyone know the
rules in Canada or Mexico?
Peter
Jerry Irvine
sock...@cs.comsockboy4atcs.com (Sockboy4) wrote:
The rules are written to apply to US citizens anywhere in the world they
launch INCLUDING international waters.
Jerry
William Mook
the US and into another nation would likely have more restrictions than
firing the IRBM in the US in the first place.
Brazil's presidente is very interested in developing missile technology. He
has set up a launch center at the Amazon river delta right on the Atlantic
Ocean, near the Equator. They're very interested in any rocket scientists
who might wish to help them in their efforts. Of course the US State
Department would be very interested in anyone wishing to help them as well.
Unfortunately, don't expect too much help from the US in this regard. Why?
Two simple words, MISSILE PROLIFERATION.
Sockboy4 <sock...@cs.comsockboy4atcs.com> wrote in message
news:20011204151949...@mb-fz.news.cs.com...
John Carmack
You can't if you are an American citizen. The US claims jurisdiction
over the actions of its citizens no matter where you are in the world,
so if you launch something without clearance from AST, you are in
trouble.
Just getting a (say) Canadian to perform the launch isn't a good idea
either, because then you are likely in violation of rocket technology
transfer rules.
In any case, if you are going to launch anything significant, you
better tell the appropriate authorities so it doesn't look like a
missile launch.
John Carmack
www.armadilloaerospace.com
Ian Woollard
> sock...@cs.comsockboy4atcs.com (Sockboy4) wrote in message news:<20011204151949...@mb-fz.news.cs.com>...
> > suppose that would only work if you are near the coast. Does anyone know the
> > rules in Canada or Mexico?
> either, because then you are likely in violation of rocket technology
> transfer rules.
Well, if the Canadian you chose was someone like Henry Spencer
or Bruce Dunn, it might be difficult to make THAT charge stick ;-)
> John Carmack
> www.armadilloaerospace.com
John F Carr
If you are suggesting that technology export is OK if the recipient
already has the technology, recall the Soviet (Russian?) nuclear
reactor that was stranded in America due to export restrictions.
We couldn't send it back to them even though they built it.
--
John Carr (j...@mit.edu)
Gordon D. Pusch
> If you are suggesting that technology export is OK if the recipient
> already has the technology, recall the Soviet (Russian?) nuclear
> reactor that was stranded in America due to export restrictions.
> We couldn't send it back to them even though they built it.
I think it highly likely that the US ``couldn't'' send it back only
because of someone's in the US Federal Gov't's insistence on a ``creative''
interpretation of the word ``export'' to achieve some desired political goal.
By any rational interpretation of the word ``import,'' that reactor was
``goods in transit, returning home:'' It was never ``imported,'' because
no one in the US received it (expropriated, it yes --- received it, no).
It could not therefore in any sense of the word have been legitimately
considered to be being ``exported'' by being returned to its country
of origin. IMO, someone in the US Gov't was clearly indulging in deliberate
obfuscation to garner some sort of political points during that incident...
-- Gordon D. Pusch
perl -e '$_ = "gdpusch\@NO.xnet.SPAM.com\n"; s/NO\.//; s/SPAM\.//; print;'
Geoffrey A. Landis
>
> j...@mit.edu (John F Carr) writes:
>
> > If you are suggesting that technology export is OK if the recipient
> > already has the technology, recall the Soviet (Russian?) nuclear
> > reactor that was stranded in America due to export restrictions.
> > We couldn't send it back to them even though they built it.
>
> I think it highly likely that the US ``couldn't'' send it back only
> because of someone's in the US Federal Gov't's insistence on a ``creative''
> interpretation of the word ``export'' to achieve some desired political goal.
The report you need is the Topaz-II: Lessons Learned report, which I
have a copy of around here somewhere, but can't seem to find at the instant.
The regulation violated was not ITAR, it was a specific law dealing with
nuclear technology, that clearly stated nuclear technology cannot be
shipped to the Soviet Union. And when the people who arranged the demo
asked the State Department about the import, they were specifically told
that they could not ship it back to Russia, but they said "oh, that's
silly," and imported the reactor anyway. The lesson learned is, don't
ignore the State Department.
> By any rational interpretation of the word ``import,'' that reactor was
> ``goods in transit, returning home:'' It was never ``imported,''
It wasn't an ITAR case, and whether it was "imported" or not is irrelevant.
However, note that the "import" of a satellite to China to be launched
into space is not import by your definition, but still it has to be
> because no one in the US received it
Huh? In what way was it not received?
> (expropriated, it yes --- received it, no).
> It could not therefore in any sense of the word have been legitimately
> considered to be being ``exported'' by being returned to its country
> of origin.
Export is not relevant to the discussion.
> IMO, someone in the US Gov't was clearly indulging in deliberate
> obfuscation to garner some sort of political points during that incident...
Probably. It is not clear, however, exactly what points were gained.
--
Geoffrey A. Landis
http://www.sff.net/people/geoffrey.landis
Just published: IMPACT PARAMETER (and other quantum realities)
http://www.goldengryphon.com/ip-frame.html
James Bowery
>
> For ascent, Jim Bowery did some simulations that seemed to indicate
> that using lift during ascent means you get less altitude- it
> optimised down to nothing.
The simulation, by Roger Gregory (modifying my application of Lester
Ingber's adaptive simulated annealer to launch simulation), was of an
expendable Roton SSTO and therefore did not include reentry costs.
Roger's result was that accelerating the blades through thin-to-none
atmosphere ended up costing as much payload mass as it bought during
ascent through atmosphere _assuming_ you had our ultracentrifugal
engine as the primary pump.
My application of Ingber's ASA, sans Roger's blade optimization
modifications, is at:
http://www.geocities.com/jim_bowery/rouasa.txt
Roger is an infamous pack rat so he may actually have that blade
optimization code still hanging around someplace (and he may even be
able to find if sufficiently interested ;-). Let me know if you want
detailed information and I'll see if he can be cajoled into parting
with it.
Geoffrey A. Landis
> >
> > For ascent, Jim Bowery did some simulations that seemed to indicate
> > that using lift during ascent means you get less altitude- it
> > optimised down to nothing.
For what it's worth, it's a relatively straightforward calculation to
show that in the equilibrium ascent case, it is optimum to use lift only
if the thrust to weight ratio is less than two-- for T/W above two, it's
optimum to ascend on direct thrust.
Rockets do not ascend in equilibrium conditions; not even in
quasi-equilibrium. Nevertheless, it's a useful end-point to note.
John Carmack
> Ian Woollard <ian.wo...@tesco.net> wrote:
> > >
> > > For ascent, Jim Bowery did some simulations that seemed to indicate
> > > that using lift during ascent means you get less altitude- it
> > > optimised down to nothing.
>
> For what it's worth, it's a relatively straightforward calculation to
> show that in the equilibrium ascent case, it is optimum to use lift only
> if the thrust to weight ratio is less than two-- for T/W above two, it's
> optimum to ascend on direct thrust.
>
Could you expand on that a bit?
John Carmack
www.armadilloaerospace.com
Henry Spencer
>> either, because then you are likely in violation of rocket technology
>> transfer rules.
>
>Well, if the Canadian you chose was someone like Henry Spencer
>or Bruce Dunn, it might be difficult to make THAT charge stick ;-)
It actually doesn't matter very much, believe it or not. Even if it is
clearly the case that the Evil Foreigner knows more than you do about the
subject, you cannot get a blanket exemption from the export rules on those
grounds. The export people still think there is some possibility that you
might let slip some small but vital item of American Know-How. You are
still required to follow onerous, time-consuming, costly procedures, such
as getting item-by-item approval for what you are allowed to discuss with
them. (If the government is really skeptical, they may insist on having
their observers present at all conversations... and *you* get to pay those
observers' travel expenses etc.)
The one near-total exception is if all information involved is public.
There has been at least one incident of a Khrunichev guy giving a public
talk about Russian launchers at (I think) the Paris Air Show, with the
Lockheed Martin guys -- Khrunichev's business partners! -- sitting in the
back frantically taking notes, because they hadn't yet been able to get
government permission to ask Khrunichev those questions in private...